docs: Improve README formatting with consistent spacing

Author: Iswanna

chat-app/README.md

@@ -3,38 +3,40 @@
 ### Backend Implementation (`backend/`)
 
 #### `server.js` (New)
+
 - Set up Express server with CORS middleware
 - Implemented **POST `/messages`** endpoint with input validation
   - Validates sender name and message text
   - Creates message objects with id, sender, text, likes, and dislikes
   - Returns 201 status on success, 400 on validation error
   - Triggers long polling callbacks to notify waiting clients
-  
 - Implemented **GET `/messages`** endpoint with long polling
   - Accepts `?since=` query parameter for incremental message loading
   - Returns only messages with id > sinceId
   - Holds client requests until new messages arrive (long polling)
   - Handles edge case where since=0 correctly
-  
 - Implemented **POST `/messages/:id/like`** endpoint
   - Increments like count for specified message
   - Notifies all waiting clients via long polling
   - Returns 200 on success, 404 if message not found
 
 #### `package.json` (New)
+
 - Configured as ES module project (`"type": "module"`)
 - Added Express 5.2.1 dependency
 - Added CORS 2.8.6 dependency
 
 ### Frontend Implementation (`frontend/`)
 
 #### `index.html` (New)
+
 - Semantic HTML structure with proper meta tags
 - Chat form with sender name and message inputs
 - Message container div for displaying chat history
 - Deferred JavaScript execution for proper DOM loading
 
 #### `script.js` (New)
+
 - **`getAllMessages()`** async function
   - Fetches messages from backend with `?since=` parameter
   - Implements incremental message loading via `lastIdSeen` tracking
@@ -56,6 +58,7 @@
   - Updates display instantly without waiting for server response
 
 #### `styles.css` (New)
+
 - Styled message containers with border, padding, and rounded corners
 - Light gray background (#f9f9f9) for message boxes
 - Styled like buttons with blue background (#007bff) and white text
@@ -64,6 +67,7 @@
 ## Testing Instructions
 
 ### Setup
+
 ```bash
 # Install backend dependencies
 cd backend
@@ -72,3 +76,4 @@ npm install
 # Start backend server
 node server.js
 
+```